mac80211: Add scan race fix
[openwrt/svn-archive/archive.git] / package / mac80211 / patches / 721-mac80211-fix-scan-race.patch
1 Index: compat-wireless-2011-02-25/net/mac80211/scan.c
2 ===================================================================
3 --- compat-wireless-2011-02-25.orig/net/mac80211/scan.c 2011-03-07 14:43:55.695666042 +0100
4 +++ compat-wireless-2011-02-25/net/mac80211/scan.c 2011-03-07 14:43:57.594439631 +0100
5 @@ -258,10 +258,12 @@ static bool ieee80211_prep_hw_scan(struc
6 return true;
7 }
8
9 -static bool __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
10 +static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
11 bool was_hw_scan)
12 {
13 struct ieee80211_local *local = hw_to_local(hw);
14 + bool on_oper_chan;
15 + bool enable_beacons = false;
16
17 lockdep_assert_held(&local->mtx);
18
19 @@ -275,12 +277,12 @@ static bool __ieee80211_scan_completed(s
20 aborted = true;
21
22 if (WARN_ON(!local->scan_req))
23 - return false;
24 + return;
25
26 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
27 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req);
28 if (rc == 0)
29 - return false;
30 + return;
31 }
32
33 kfree(local->hw_scan_req);
34 @@ -294,26 +296,13 @@ static bool __ieee80211_scan_completed(s
35 local->scanning = 0;
36 local->scan_channel = NULL;
37
38 - return true;
39 -}
40 -
41 -static void __ieee80211_scan_completed_finish(struct ieee80211_hw *hw,
42 - bool was_hw_scan)
43 -{
44 - struct ieee80211_local *local = hw_to_local(hw);
45 - bool on_oper_chan;
46 - bool enable_beacons = false;
47 -
48 - mutex_lock(&local->mtx);
49 on_oper_chan = ieee80211_cfg_on_oper_channel(local);
50
51 WARN_ON(local->scanning & (SCAN_SW_SCANNING | SCAN_HW_SCANNING));
52
53 - if (was_hw_scan || !on_oper_chan) {
54 - if (WARN_ON(local->scan_channel))
55 - local->scan_channel = NULL;
56 + if (was_hw_scan || !on_oper_chan)
57 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
58 - } else
59 + else
60 /* Set power back to normal operating levels. */
61 ieee80211_hw_config(local, 0);
62
63 @@ -331,7 +320,6 @@ static void __ieee80211_scan_completed_f
64 }
65
66 ieee80211_recalc_idle(local);
67 - mutex_unlock(&local->mtx);
68
69 ieee80211_mlme_notify_scan_completed(local);
70 ieee80211_ibss_notify_scan_completed(local);
71 @@ -686,12 +674,14 @@ void ieee80211_scan_work(struct work_str
72 {
73 struct ieee80211_local *local =
74 container_of(work, struct ieee80211_local, scan_work.work);
75 - struct ieee80211_sub_if_data *sdata = local->scan_sdata;
76 + struct ieee80211_sub_if_data *sdata;
77 unsigned long next_delay = 0;
78 - bool aborted, hw_scan, finish;
79 + bool aborted, hw_scan;
80
81 mutex_lock(&local->mtx);
82
83 + sdata = local->scan_sdata;
84 +
85 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
86 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
87 goto out_complete;
88 @@ -755,17 +745,11 @@ void ieee80211_scan_work(struct work_str
89 } while (next_delay == 0);
90
91 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
92 - mutex_unlock(&local->mtx);
93 - return;
94 + goto out;
95
96 out_complete:
97 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
98 - finish = __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
99 - mutex_unlock(&local->mtx);
100 - if (finish)
101 - __ieee80211_scan_completed_finish(&local->hw, hw_scan);
102 - return;
103 -
104 + __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
105 out:
106 mutex_unlock(&local->mtx);
107 }
108 @@ -835,7 +819,6 @@ int ieee80211_request_internal_scan(stru
109 void ieee80211_scan_cancel(struct ieee80211_local *local)
110 {
111 bool abortscan;
112 - bool finish = false;
113
114 /*
115 * We are only canceling software scan, or deferred scan that was not
116 @@ -855,14 +838,17 @@ void ieee80211_scan_cancel(struct ieee80
117
118 mutex_lock(&local->mtx);
119 abortscan = local->scan_req && !test_bit(SCAN_HW_SCANNING, &local->scanning);
120 - if (abortscan)
121 - finish = __ieee80211_scan_completed(&local->hw, true, false);
122 - mutex_unlock(&local->mtx);
123 -
124 if (abortscan) {
125 - /* The scan is canceled, but stop work from being pending */
126 - cancel_delayed_work_sync(&local->scan_work);
127 + /*
128 + * The scan is canceled, but stop work from being pending.
129 + *
130 + * If the work is currently running, it must be blocked on
131 + * the mutex, but we'll set scan_sdata = NULL and it'll
132 + * simply exit once it acquires the mutex.
133 + */
134 + cancel_delayed_work(&local->scan_work);
135 + /* and clean up */
136 + __ieee80211_scan_completed(&local->hw, true, false);
137 }
138 - if (finish)
139 - __ieee80211_scan_completed_finish(&local->hw, false);
140 + mutex_unlock(&local->mtx);
141 }